the necklace thief

[toshiro]

Hi I am going through OC once more. This time I am skipping most subquests. However I am particularily interested in the "stolen necklace" subquest.
I've heard that it's possible to catch the thief. I DO know where to find the necklace - I want the thief! :D
I tryed the typical OC "capture-the-thief" routine where you hide somewhere or maybe use invisibility and wait for the thief to make his move, alas with no success.
Does anyone know how to get him?
/I am posting this in all still active OC forums :)/